Table 1.

Operational definition of variables

Variables		Measurements	Definition
Dependent	MDR Resistance	Discrete	Does the patient acquire a MDR infection during hospitalization? Yes or No
Independent	Sex	Discrete	Sex of the patients, Male or Female.
	Age	Continous	Age (in years) during hospitalization
	Age Class	Discrete	10 years class to witch the patient belong, from 1 to 10
	Ward	Discrete	Ward where the patient was hospitalized, from 1 to 11
	Time Period	Discrete	Time period in which the patient was hospitalized in a ward, from 1 to 14